"Sat, 17 Jan 1970 04:40:21"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700117
Only TIME
04:40:21
General datetime
1970-01-17 04:40:21Z
For Database
1970-01-17 04:40:21
For HTTP1.1
Sat, 17 Jan 1970 04:40:21 GMT